In this ancillary study to the Multiple Risk Factor Intervention Trial, the basic aim is to assess the ability of a non-invasive objective measurement of myocardial functional status to predict prognosis - (particularly risk of mortality from CHD and risk of myocardial infarction) in men who are at high risk of developing coronary heart disease. Three clinical centers located in Baltimore, Chicago, and Minneapolis, with 2100 high risk males ages 35 through 54 to be entered into the program during the calendar year 1974. These subjects will be randomized into a control group and a treatment group and followed for 6 years. The three centers will be 100% in this effort in accordance with a common protocol. The ultralow frequency ballistocardiogram will be used to evaluate myocardial functional status. ULFBCG's will be tape recorded and evaluated by computer in the Biomedical Engineer Department of Johns Hopkins (Dr. W.K. Harrison, Jr.). The ULFBCG will be recorded at entry, during the second and fourth year of the program to assess the effects of intervention on risk factors on the ULFBCG. All subjects will be followed for six years to assess mortality and morbidity from CHD. Extensive data on multiple variables will be accrued from MRFIT Coordinating Center Files. Particular attention will be given to modern multivariate methods of statistical analysis using control group data in order to evaluate the key question of the independent predictive power of the ULFBCG.